(1) Scorch stage, also known as the curing induction period, at
this stage, cross-linking has not yet begun, the compound in the
model have good mobility. Rubber vulcanization start speed,
directly affect the rubber scorch and operation safety.

(2) Pre-sulfur phase, after the scorch rubber began to
cross-linking stage. At this stage, due to low degree of
cross-linking, rubber products should have most of the
performance is not obvious. However, the late stage of this
stage, the product slightly sulfur, although the product tensile
strength, elasticity, elongation and so has not yet reached the
desired level, but its anti-tear wear resistance and dynamic
crack resistance is better than Vulcanized rubber compound.

(3) The sulfur phase, in most cases, the vulcanization products
must be made to achieve the appropriate degree of cross-linking,
to achieve the appropriate degree of our joint phase is called
vulcanization, the sulfur phase. At this s

tage, the physical and mechanical properties of vulcanized rubber
are not at the same time reached the highest value, but were
close to or close to the best value, the best overall
performance. The temperature and time taken at this stage are
called the normal vulcanization temperature and the positive cure
time.

(4) Over-sulfur phase, after the sulfur phase, continue to enter
the sulfur curing stage. Cross-linking reaction and oxidation and
thermal chain-breaking reaction throughout the rubber
vulcanization process always, but at different stages, these two
reactions occupy different status, in the sulfur phase oxidation
and thermal chain-off reactions are often dominant, Therefore,
there will be physical and mechanical properties of rubber
material decreased phenomenon.